JPH03138453A - Start controller for engine - Google Patents

Abstract

PURPOSE:To prevent the start disorder by installing a voltage detecting means and an autostart frequency setting means, setting the autostart frequency of a self-starter/altenator low according to the lowering of the battery voltage and permit the output torque necessary for start to be generated also in the lowering of the battery voltage. CONSTITUTION:When an ignition switch 6 is turned ON, a control unit 2 starts control, and when a starter switch signal is inputted from a signal wire 2a, the autostart frequency is calculated and set on the basis of a map. The map is set by setting the autostart frequency and the battery voltage as parameters, and the autostart frequency is set to lower according to the lowering of the battery voltage. Accordingly, an excitation current is supplied into a field coil 15 through a field coil controller 4, and a rotary magnetic field which revolves with the autostart frequency set in the above-described is generated on a stator coil 17 in three phase through an inverter 3, and an engine E is cranking- operated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an engine starting control device, and more particularly to an engine starting control device including a selternator that serves both as a starter motor and a generator.

[Prior art]

Recently, as described in, for example, Japanese Unexamined Patent Application Publication No. 61-54949, a selternator having the functions of both a starter motor and a power generation alternator has been put into practical use for automobile engines.

This selternator generally consists of a rotating field pole provided on the outer periphery of an engine flywheel, a field coil wound around a field core radially inside the rotating field pole to excite the rotating field pole, and a field coil radially outside the rotating field pole. A selternator body including a stator provided in the engine and a three-phase stator coil wound around the stator, and this selternator body is operated as a starting motor when starting the engine and as a generator when the engine is running. It is equipped with a control device that controls the

When operating the selternator as a starter motor, it is necessary to supply controlled three-phase excitation current to the three-phase stator coils so that a rotating magnetic field corresponding to the phase of the rotating field poles is generated. Optimal torque can be obtained when the phase of the rotating magnetic field relative to the phase of the magnetic poles is set to the optimal phase.

Further, when the selternator is operated as a generator, the generated current generated in the stator coil is simply taken out through the rectifier circuit, and there is no need to control the stator coil.

Here, when starting the engine using the selternator, first the selternator is started automatically and self-start control for detecting the reference position for phase control is executed, and after the reference position is detected by self-starting, the stator coil is Phase control is performed to make the phase of the rotating magnetic field the optimum phase.

The self-starting control described above changes the phase of the three-phase excitation current supplied to the stator coil at a constant frequency, and is a control that drives the stator coil without corresponding to the phase of the rotating field poles. In this case, since the phase of the rotating magnetic field of the stator coil is not optimally set, the rotation speed of the output shaft of the engine is only about 50 rpm.

When the selternator is started by the self-starting control described above, the reference position of the rotating field pole is determined by the signal from the reference position detection sensor, so that the phase of the rotating magnetic field of the stator coil with respect to the phase of the rotating field pole becomes the optimum phase. A controlling phase control is carried out, which ensures that the engine is started with optimum torque.

[Problem to be solved by the invention]

The relationship between the self-starting frequency, engine speed, and output torque when the selternator is started automatically when starting the engine is as shown in Figure 8. The lower the frequency, the greater the output torque of the selternator.

On the other hand, in an automobile engine, power is supplied from the battery to the field coil and stator coil of the selternator, but as shown in Figure 9, the battery voltage fluctuates depending on the degree of charge, and the battery voltage decreases. The output torque of the selternator decreases accordingly.

However, with conventional selternators, the self-starting frequency at startup is set to a predetermined frequency regardless of battery voltage, so if the battery voltage is low, the selternator's output torque is insufficient. There was a problem in that it became difficult to start the engine.

An object of the present invention is to provide an engine starting control device that increases starting reliability by setting a self-starting frequency according to battery voltage.

[Means to solve the problem]

An engine starting control device according to the present invention includes a rotating field pole provided on the outer periphery of an engine flywheel, a field coil wound around a field core radially inside the rotating field pole, and a rotating field coil that excites the rotating field pole. A selternator body includes a stator provided on the radially outer side of the magnetic poles and a three-phase stator coil wound around the stator, and this selternator body is operated as a starting motor when starting the engine, and when the engine is running. An engine equipped with a selternator having a control means for controlling the selternator to operate as a generator, comprising: a battery for supplying power to the field coil and the stator coil; a voltage detection means for detecting the voltage of the battery; The self-starting frequency setting means receives the output and sets the self-starting frequency for self-starting the selternator main body when starting the engine so that it becomes lower as the battery voltage decreases.

[Effect]

In the engine starting control device according to the present invention, when starting the engine using the selternator, power is supplied from the battery to the field coil and the stator coil, and the voltage of the battery is detected by the voltage detection means.

The self-starting frequency setting means receives the output of the voltage detecting means and sets the self-starting frequency when starting the engine so that it becomes lower according to the drop in battery voltage. This generates a sufficient output torque and does not cause engine starting problems.

〔Effect of the invention〕

According to the engine starting control device according to the present invention, the above [
As explained in the section [Operation], by providing a voltage detection means and a self-starting frequency setting means, and setting the self-starting frequency of the selternator to a low value in response to a decrease in battery voltage,
Even when the battery voltage drops, the output torque necessary for starting is generated, and the engine does not start incorrectly.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

This embodiment is an example in which the present invention is applied to a vertical four-cylinder automobile engine that incorporates a selternator that serves both as a starter motor and as a generator.

The selternator includes a selternator main body 1 built into an engine E, a control unit 2, an inverter 3, a field coil controller 4, etc., as shown in FIG.

The selternator main body 1 will be explained.

As shown in FIGS. 1 to 3, the selternator zero body 1 is
A rotating field pole 12 provided on the outer periphery of a flywheel 11 fixed to the shaft end of the crankshaft 10 of the engine E;
A field core 14 fixedly provided on the engine body 13 on the inside in the radial direction and this field core 1
The field coil 15 wound around the rotating field pole 1
A stator core 16 is fixedly provided on the engine body 13 on the radially outer side of the stator core 16, and a three-phase stator coil 1 of U-phase, V-phase, and W-phase is wound around the stator core 16.
It consists of 7 etc.

As shown in FIG. 2, the rotating field pole 12 includes a first ball core 20 having a large number of pawls 20a integrally formed on the outer periphery of the flywheel 11 at predetermined intervals in the circumferential direction toward the engine body 13. and a second pole core 21 having a large number of claws 21a located between the winter melons 20a of the first pole core 20 and facing away from the engine body 13, and the first and second pole cores 20 and 21 with their claws. 20a
- It is composed of a non-magnetic ring 22 that is coupled inside the tip of the ring 21a.

The field core 14 around which the field coil 15 is wound is fixed to the end face of the engine body 13 via an aluminum plate 18 that blocks magnetic fields.
The field coil 15 is disposed within an annular recess 11 a recessed in the radially outer portion of the flywheel 11 on the side of the engine body 13 such that the outer peripheral surface of the rotating field pole 4 approaches and opposes the inner peripheral surface of the rotating field pole 12 . It is arranged. A minute gap is provided between the opposing surfaces of the field core 14, flywheel 11, and rotating field pole 12.

The stator core 16 is an annular body formed by laminating a large number of steel plates, and as shown in FIG. 3, a large number of slits 16a are formed on the inner circumference side over the entire width at predetermined intervals in the circumferential direction. The stator core 16 is arranged on the outside of the flywheel 11 in the radial direction and is fixed to an annular frame 23 sandwiched between the engine body 13 and the flywheel housing 19.
) is wound in distributed winding around the slit 16a of the stator core 16, and is connected to the inner surface of the stator core 16 and the rotating field pole 12.
are opposed to each other, and a minute gap is provided between them.

Note that the flywheel 11 has a torque converter 24.
Input section 2 of automatic transmission A consisting of a gear section (not shown) and a gear section (not shown)
Cooling water pipes 26 and 27 are provided inside the field coil 15 and on both sides of the outer periphery of the stator coil 17 to flow cooling water, respectively.

The selternator zero body 1 functions as a 3-phase AC motor by supplying 3-phase excitation current to the 3-phase stator coil 17 while the field coil 15 is energized when the engine E is started. Inside, it functions as a three-phase alternating current generator that generates electricity with the three-phase stator coil 17 when the field coil 15 is energized.

Next, the control system of the selternator will be explained.

As shown in FIG. 4, this control system includes a control unit 2, a field coil controller 41 that controls energization to the field coil 15, and an inverter 3 that controls energization to the stator coil 17.
When the ignition switch 6 is turned on, the control unit 2 directly outputs information from the battery 5.
Also, field coil controller 4 and inverter 3
are supplied with power via relays 7, respectively.

Furthermore, a disk plate 30 is fixed to the shaft end of the crankshaft 10 of the engine E on the side opposite to the automatic transmission A, and the outer circumference of the disk plate 30 has a circumference of 6, for example.
Slits are formed at equal positions, and a first proximity switch 8 for reference detection is provided in the engine body 13 at a radial position corresponding to the slit, and the signal from this first proximity switch 8 is amplified by an amplifier 31. It is then supplied to the control unit 2. The first proximity switch 8 outputs an "H" level signal when not facing the slit, and outputs an "L" level reference position signal when facing the slit. Furthermore, slits are formed in a portion of the disc plate 30 on the inner circumferential side than the slits, for example, at 360 equal positions on the circumference, and at radial positions corresponding to the slits, a second proximity sensor for detecting the crank angle is formed on the engine body 13. A switch 9 is provided, and the signal from the second proximity switch 9 is amplified by an amplifier 32 and then supplied to the control unit 2. The second proximity switch 9 outputs an "H" level signal when not facing the slit, and outputs a "L" level crank angle signal when facing the slit.

The control unit 2 includes a waveform shaping circuit for shaping signals from the first and second proximity switches 8 and 9, and an A/D converter 2 for detecting the battery voltage of the battery 5.
b, is equipped with an A/D converter 2b that A/D converts the input terminal of the signal line 2a from the starter terminal 6b of the ignition 12 switch 6, an input/output interface, a microcomputer, etc., and is equipped with a microcomputer. The ROM (read only memory) is loaded with 3 data via inverter 3 when engine E is started.
A control program for self-starting control that automatically starts the selternator zero body 1 by supplying three-phase alternating current with a self-starting frequency set by the following self-starting frequency setting control to the stator coil 17 of each phase; 1
When the stator coil 17 starts automatically, the phase of the rotating magnetic field of the stator coil 17 with respect to the phase of the rotating field pole 12, which rotates with the number of rotations increasing moment by moment using the signals from the first and second proximity switches 8 and 9, becomes the target phase. A phase control control program for operating the selternator zero body 1 to output the optimum torque by supplying three-phase alternating current with a frequency that varies according to the rotation speed to the three-phase stator coil 17 so that the engine E A control program for self-starting frequency setting control that sets the self-starting frequency according to the battery voltage when starting the selternator using the above-mentioned self-starting control at the time of starting, the accompanying map shown in FIG. 7, and a field coil controller at the time of starting and power generation. A control program for controlling the excitation current to the field coil 15 via the field coil 4 (however, this is included in the self-start control control program and the phase control control program), etc. are input and stored in advance.

The inverter 3 will be explained based on FIG. 5.

Three sets of current control circuits 34u, 34v, and 34w corresponding to the three phases U, ■, and W are connected in parallel between the positive and negative electrodes of the battery 5, and these current control circuits 34u, 34v, and
Enhancement MO3 connected in series to each 34w
Switching elements 35 to 40 made of type FETs are provided, and diodes 41 to 46 are connected in parallel to each switching element 35 to 40 so as to pass current from the negative electrode side to the positive electrode side of the battery 5, and each current control circuit 34U・3
The circuit between the switching elements 33 4 5 to 40 in 4V/34W has a corresponding U of the stator coil 17.
Phase coil 17u-V phase coil 17v-W phase coil 17w
are connected to the gates of the switching elements 35 to 40, respectively, and signal lines 35a to 4 from the control unit 2 are connected to the gates of the switching elements 35 to 40, respectively.
0a is connected.

When starting the engine E, the switching elements 35 to 40 are intermittently turned ON and OFF in a predetermined combination and sequence by a control pulse signal from the control unit 2 while the field coil 15 is energized. A phase current is supplied to generate a rotating magnetic field, and the magnetic force of the rotating magnetic field acts on the rotating field pole 12 to rotate the flywheel 11 and crankshaft 10 in the normal rotation direction, thereby starting the engine E. In other words, the selternator functions as a three-phase AC motor.

Moreover, while the engine E is operating, the switching elements 35 to 4
When the rotating field pole 12 excited by the field coil 15 rotates together with the flywheel 11 while the 0 is held OFF, the three-phase coil 17 of the stator coil 17
An alternating current induced current is generated in u·17v17w, which is rectified by a rectifier circuit including diodes 41 to 46 and supplied to the battery 5. In other words, the selternator functions as an alternator.

Next, starting control including self-starting frequency setting control executed by the control unit 2 when starting the engine E will be explained based on the flowchart of FIG. 6. However, 5t (i=1.2.3, . . . ) in the figure indicates each step.

When the ignition switch 6 is turned on and connected to the ignition terminal 6a, power is supplied to the control unit 2 to start control, and necessary initialization is performed on the RAM (random access memory) (Sl). Next, the starter switch signal is transmitted from the signal line 2a to the A/D converter 2.
(S2), it is determined whether the starter switch signal is ON or not (S3), and as long as the starter switch signal is OFF, S2 and S3 are repeated, but in order to start the engine E. When the ignition switch 6 is connected to the starter terminal 6b and the starter switch signal is turned ON, the battery voltage Vo is read from the signal line 2a via the A/D converter 2b (S4), and then at 35, the voltage shown in FIG. The self-starting frequency fo is calculated and set using the map (S5).

FIG. 7 shows the isotorque line T of the output torque of the selternator using the self-starting frequency f and the battery voltage V as parameters, ~
It is difficult to self-start in a torque region smaller than the equal torque line T2, so in order to ensure self-start, the battery must be adjusted so that the torque is larger than the equal torque line T2. Self-starting frequency f in relation to voltage V
It is necessary to set Therefore, in order to increase the number of rotations for self-starting as much as possible and ensure self-starting, an isotorque line T with a torque slightly larger than the isotorque line T2 is set using the self-starting frequency f and the battery voltage V as parameters. A map is input and stored in the control program in advance as a map, and using this map, the self-starting frequency fO is determined from the detected battery voltage Vo as shown in the figure. Next 3
At 6, self-starting control for self-starting the selternator main body 1 is executed at the self-starting frequency set at 35.

This self-starting control is similar to existing well-known control, so to briefly explain it, a control signal is output to the field coil controller 4 to supply an excitation current of a predetermined voltage to the field coil 15, and the signal line is controlled in a predetermined combination and sequence. By outputting a negative voltage control pulse signal to 35a to 40a, the switching elements 35 to 40 are turned on in a predetermined combination and sequence, and the three-phase stator coil 1 is turned on.
7, generate a rotating magnetic field that rotates at the self-starting frequency set above. In this case, the current flow in the stator coil 17 is, for example, U-phase coil 17u-+v-phase coil 17v-
W phase coil 17w, U phase coil 17u, ■ phase coil 17
v-+W phase coil 17W.

■Phase coil 17v-+W-phase coil 17w-U-phase coil 1
7u, V-phase coil 17v-W-phase coil 17w→U-phase coil 17u, and so on, are switched at minute intervals of 78 times.

The self-start control execution of S6 actually involves the signal lines 35a to 40.
This means the output of a control pulse signal to a, and the reference position signal from the first proximity switch 8 is read every time it is output (S7
), Next, it is determined whether the reference position signal is at rL, t level, that is, whether any of the six slits corresponding to the reference position of the crankshaft 10 or flywheel 11 matches the position of the first proximity switch 8. (38), and if the answer is No, the process returns to S6 and S6 to S8 are repeated.
starts and the crankshaft 10 rotates by a small angle (maximum 60 degrees).
If the determination in S8 is Yes, it is determined that the self-starting control should be ended (S9) (however, this step can be omitted).

Next, in step 310, phase control is performed so that the phase of the rotating magnetic field of the stator coil 17 with respect to the phase of the rotating rotating field pole 12 becomes a preset target phase. This phase control is similar to existing well-known control, so to briefly explain it, a control signal is output to the field coil controller 4 to supply an excitation current of a predetermined voltage to the field coil 15, while controlling the crank angle from the second proximity switch 9. The rotation speed is determined based on the signal, and the inverter 3 is controlled so that the phase of the rotating magnetic field of the stator coil 17 becomes the target phase relative to the phase of the rotating field pole 12 obtained based on the reference position signal from the first proximity switch 8. A pulse signal is output, and the switching elements 35 to 40 are turned on in a predetermined combination and sequence as described above. Each time the output of these control pulse signals is completed, a shift is made from SIO to Sll, a crank angle signal is read (Sll), and the engine rotation speed Ne is calculated based on the crank angle signal <312)
. However, if the engine rotation speed Ne obtained in step 310 is used, steps 311 and 312 can be omitted. Next, it is determined whether the engine rotation speed Ne is equal to or higher than the start determination rotation speed Ns (S13), and when Ne<Ns, the process returns to S10.
10 to S13 are repeated. In this way, phase control is executed and the engine rotational speed Ne also increases. As a result, when Ne≧Ns, the starting of the engine E is completed by 9 0 , so the process moves from S13 to 314, where it is determined to end the phase control and the control ends.

Next, the operation of the self-starting frequency setting control of the engine described above will be explained.

As mentioned above, when the engine E starts, the battery voltage Vo
The battery voltage V Engine E can be reliably started without any starting failure caused by a decrease in engine speed.

Note that the A/D converter 2 is used to detect the voltage of the battery 5.
Instead of b, a voltage detection sensor may be provided on the output line of the battery 5 closer to the battery 5 than the ignition switch 6 for detection.

[Brief explanation of the drawing]

1 to 7 show embodiments of the present invention. FIG. 1 is a longitudinal sectional view of the selternator main body, etc., FIG. 2 is a partial perspective view of the selternator main body, and FIG. 3 is a view of the stator core and stator coil. FIG. 4 is an overall configuration diagram of the selternator incorporated into the engine, FIG. 5 is a configuration diagram of the inverter and stator coil, FIG. 6 is a flowchart of the startup control routine including self-starting frequency setting control, and FIG. The figure is a characteristic diagram of a self-starting frequency setting map including equal torque lines with self-starting frequency and battery voltage as parameters, and Fig. 8 shows the torque of a selternator according to the prior art with engine speed and self-starting frequency as parameters. The characteristic diagram, FIG. 9, is a characteristic diagram of the output torque of the selternator using the battery voltage as a parameter according to the prior art. E...Engine, 1...Selternator body, 2...
Control unit, 2b...A/D converter,
3. Inverter, 4. Field coil controller, 5. Battery, 8. First proximity switch,
9...Second proximity switch, 11...Flywheel, 12...Rotating field pole, 14...Field core, 15...Field coil, 16...Stator 1 2 core, 17...Stator coil. Patent applicant Mazda Corporation 3 JP 3 138453 (11) Ward + I4 to 1 hee Ward -) IR 2 run to 1 + l Self to he - he e Aji 442-

Claims (1)

[Claims] (1) A rotating field pole provided on the outer periphery of the engine flywheel, a field coil wound around a field core radially inside the rotating field pole to excite the rotating field pole, and a field coil provided radially outside the rotating field pole. A selternator body including a stator and a three-phase stator coil wound around the stator, and a selternator body that is controlled to operate as a starting motor when starting the engine and as a generator while the engine is running. In the engine, the engine is equipped with a selternator, which has a battery that supplies power to the field coil and the stator coil, a voltage detection means that detects the voltage of the battery, and a selternator that receives the output of the voltage detection means and receives the output of the voltage detection means when the engine is started. An engine starting control device comprising: self-starting frequency setting means for setting a self-starting frequency when self-starting a selternator body to become lower in accordance with a decrease in battery voltage.